1. Running Hydration Backpack - This running hydration vest is designed for running/road cycling/hiking. The backpack weighs 250g/8.82oz, which is super light and greatly reduces the burden when running.The running vest is made of nylon elastic fabric, which is comfortable and durable. 2. Comfortable Back System - Lightweight cycling backpack back lining and shoulder straps are all made of lightweight, breathable mesh fabric speeds up air-flow which can keep your back dry and comfortable while hiking. Soft shoulder strap edges prevent the pack from chafing your skin. 3. Ergonomic and Contoured Design - Ergonomic hiking backpack hydration vest aligns your back while gently protecting your muscles. Adjustable chest straps and waist straps can reduce the burden of shoulders make a backpack perfect fit reducing bounce and keep the balanced. 4. 6 Security Storage Pocket - The running vest has a total of 6 external pockets with a capacity of 5.5L, the water bottle compartment on the chest can hold two 250ML soft water bottles, and the hydration compartment on the back is compatible with 1.5L water bags. The remaining pockets allow you to store small items such as keys, cell phones, tissues and cash. These pockets also protect your valuables and are very practical and convenient. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-Dadangjia